from skimage import filters
sobel_h()函数、sobel_v()函数、sobel()函数
from skimage import feature
edges1 = feature.canny(im)
edges2 = feature.canny(im, sigma=2)
from skimage import transform
from skimage.transform import pyramid_gaussian
pyramid = pyramid_gaussian(image, downscale=2)
拉普拉斯金字塔
递归地获得平滑和向下采样的图像
im1 = rescale(im1,scale=0.5,multichannel=True,anti_aliasing=True)